convert to upper case in js code example

Example 1: uppercase javascript

var str = "Hello World!";
var res = str.toUpperCase();  //HELLO WORLD!

Example 2: to upper javascrit

var str = "Hello World!";
var res = str.toUpperCase();

Example 3: how to convert array to uppercase in javascript

var a = ['this','is','test'];

a.map(f=>{ return f.toUpperCase(); });